1. Field of the Invention
The present invention relates to an electrolytic solution containing a solvent and a secondary battery using it.
2. Description of the Related Art
In recent years, portable electronic devices such as combination cameras (videotape recorder), mobile phones, and notebook personal computers have been widely used, and it is strongly demanded to reduce their size and weight and to achieve their long life. Accordingly, as a power source of the portable electronic devices, a battery, in particular a light-weight secondary batter capable of providing a high energy density has been developed.
Specially, a secondary battery using insertion and extraction of lithium for charge and discharge reaction (so-called lithium ion secondary battery) and a secondary battery using precipitation and dissolution of lithium (so-called lithium metal secondary battery) are extremely prospective, since such a secondary battery is able to provide a higher energy density compared to a lead battery and a nickel cadmium battery.
For a composition of the electrolytic solution used for the secondary batteries, to improve the battery characteristics such as cycle characteristics, technologies using a compound having a sulfonyl group (—S(═O)2—) (sulfone compound) have been proposed. As the sulfone compound, a chain or cyclic compound having —S(═O)2—O—C(═O)— bond (an anhydride of sulfonic acid and carboxylic acid: for example, refer to Japanese Unexamined Patent Application Publication No. 2002-008718), a cyclic compound having —S(═O)2—O—S(═O)2— bond (disulfonic acid anhydride: for example, refer to Japanese Unexamined Patent Application Publication No. 2004-022336), a cyclic compound having —S(═O)2—S—C(═O)— bond (for example, refer to Korean Unexamined Patent Application Publication No. 2002-0041646) and the like have been used.